This package implements the doctools table of contents import plugin
for the parsing of doctoc markup.

This is an internal package of doctools, for use by the higher level
management packages handling tables of contents, especially doctools::toc::import, the import manager.

Using it from a regular interpreter is possible, however only with
contortions, and is not recommended.
The proper way to use this functionality is through the package
doctools::toc::import and the import manager objects it
provides.

This command takes the string and parses it as doctoc
markup encoding a table of contents, in the context of the specified
configuration (a dictionary). The result of the command is the
canonical serialization of that table of contents, in the form
specified in section ToC serialization format.

Here we specify the format used by the doctools v2 packages to
serialize tables of contents as immutable values for transport,
comparison, etc.

We distinguish between regular and canonical
serializations.
While a table of contents may have more than one regular serialization
only exactly one of them will be canonical.

regular serialization

The serialization of any table of contents is a nested Tcl dictionary.

This dictionary holds a single key, doctools::toc, and its
value. This value holds the contents of the table of contents.

The contents of the table of contents are a Tcl dictionary holding the
title of the table of contents, a label, and its elements. The
relevant keys and their values are

title

The value is a string containing the title of the table of contents.

label

The value is a string containing a label for the table of contents.

items

The value is a Tcl list holding the elements of the table, in the
order they are to be shown.

Each element is a Tcl list holding the type of the item, and its
description, in this order. An alternative description would be that
it is a Tcl dictionary holding a single key, the item type, mapped to
the item description.

The two legal item types and their descriptions are

reference

This item describes a single entry in the table of contents,
referencing a single document.
To this end its value is a Tcl dictionary containing an id for the
referenced document, a label, and a longer textual description which
can be associated with the entry.
The relevant keys and their values are

id

The value is a string containing the id of the document associated
with the entry.

label

The value is a string containing a label for this entry. This string
also identifies the entry, and no two entries (references and
divisions) in the containing list are allowed to have the same label.

desc

The value is a string containing a longer description for this entry.

division

This item describes a group of entries in the table of contents,
inducing a hierarchy of entries.
To this end its value is a Tcl dictionary containing a label for the
group, an optional id to a document for the whole group, and the list
of entries in the group.
The relevant keys and their values are

id

The value is a string containing the id of the document associated
with the whole group. This key is optional.

label

The value is a string containing a label for the group. This string
also identifies the entry, and no two entries (references and
divisions) in the containing list are allowed to have the same label.

items

The value is a Tcl list holding the elements of the group, in the
order they are to be shown.
This list has the same structure as the value for the keyword
items used to describe the whole table of contents, see
above. This closes the recusrive definition of the structure, with
divisions holding the same type of elements as the whole table of
contents, including other divisions.

canonical serialization

The canonical serialization of a table of contents has the format as
specified in the previous item, and then additionally satisfies the
constraints below, which make it unique among all the possible
serializations of this table of contents.

The keys found in all the nested Tcl dictionaries are sorted in
ascending dictionary order, as generated by Tcl's builtin command
lsort -increasing -dict.

This document, and the package it describes, will undoubtedly contain
bugs and other problems.
Please report such in the category doctools of the
Tcllib Trackers.
Please also report any ideas for enhancements you may have for either
package and/or documentation.

Note further that attachments are strongly preferred over
inlined patches. Attachments can be made by going to the Edit
form of the ticket immediately after its creation, and then using the
left-most button in the secondary navigation bar.